Placement selection of millimeter wave FMCW radar for indoor fall detection

Indoor fall detection based on radar technology has recently drawn more and more attention because of the advantages of privacy protection, all-day working and non-intrusive properties. Numerous studies have used Micro-Doppler information to extract fall signatures. However, mounting position of a radar sensor has a great influence on the Doppler response and fall signature extraction. In this work, we demonstrate the effects of radar placements on micro-Doppler and range intensity. For this purpose, we first use an approximation rigid-motion model to analyze the process of a fall. Then time-frequency distribution and range-time intensity are used as the input data for feature extraction. A millimeter wave frequency modulated continuous wave (FMCW) radar with 3-GHz bandwidth is mounted on three positions to detect the action of human fall. Experimental results show that well selected placement of the radar sensor can provide improved feature extraction results both from micro-Doppler and range-time intensity.